Taura Syndrome - Overview

Overview

The 1992 Ecuadorian TS epidemic occurred concurrently with an outbreak of black leaf wilt disease in banana plantations. The outbreak of black leaf disease led to an increase in fungicide usage within the Taura River basin district near the city of Guayaquil. The fungicides propiconazole (Tilt, Ciba-Geigy) and tridemorph (Calixin, BASF) used to control black leaf, ran off into nearby ponds and were responsible for the disease. Analytical data demonstrated propiconazole in water, sediments and hepatopancreas tissues of shrimp harvested from affected farms in Ecuador. No other pesticides were discovered.

In January 1994, at the request of Ciba-Geigy, a workshop on Taura syndrome was held at the Aquaculture Pathology Laboratory of the University of Arizona. Experts from several countries with expertise in shrimp and insect pathology, shrimp nutrition, toxicology, myocology, water quality and farm management participated in the workshop. Industry representatives also participated. The group developed recommendations as to the standardization of the research on TS and suggested that studies be done to evaluate whether fungicides or as-yet unrecognized agents were responsible for the syndrome.

Dr. Jim Brock, the aquatic disease specialist for the State of Hawaii during this period, first demonstrated the disease could be transmitted by feeding Taura victims to healthy shrimp in early 1994. The dying test shrimp were then fed to a new set of shrimp, which was dying at the same rate. Rivers' postulates were fulfilled in 1994 by Dr. Ken Hasson and co-researchers at the University of Arizona. This proved the viral etiology of the syndrome. The virus was named Taura syndrome virus, often referred to as TSV. The virus is referred to by the name infectious cuticular epithelial necrosis virus (ICENV) by some authors in Latin America. Taura syndrome is a notifiable disease by the Office international des Épizooties (OIE), which reflects the serious nature and devastating impact of the disease.